1. Field of the Invention
The present invention relates to a video and audio system, and more particularly, to a video and audio system capable of saving electric power.
2. Description of the Prior Art
Please refer to FIG. 1, which is a diagram of a TV system 1 according to the prior art. The TV system 1 comprises a TV tuner 11, an audio processor 13, a TV decoder 15, a main integrated circuit (IC) 14, a power management unit 12, and a power supply 10.
The main IC 14 comprises a microcontroller unit (MCU) 142 and a video processor 141. The MCU 142 controls the operations of the TV tuner 11, the audio processor 13, the TV decoder 15, and the video processor 141. The power management unit 12 receives electric power from the power supply 10, and provides required operation voltages to the TV tuner 11, the audio processor 13, the TV decoder 15, and the main IC 14 correspondingly.
When the TV system 1 is turned off, the MCU 142 sends signals to the TV tuner 11, the audio processor 13, the TV decoder 15, and the video processor 141 to stop all operations. However, the MCU 142 must be in operation all the time to receive input signals, such as signals related to turning on the TV system 1 or setting the time. Since the MCU 142 must react to all input signals immediately, the path of electric power cannot be disconnected, resulting in a constant small current flow from the power management unit 12 to the TV tuner 11, the audio processor 13, and the TV decoder 15. This wastes electric power. With the current trend towards natural and green goods, saving power has become important.